[xen-tools-discuss] DRBD configurations

[Sam Howard]

Hi.
I've just started playing with xen-tools now that I am building a new pair
of Xen servers (on Ubuntu Hardy), and I have a few questions ...

How hard is it to tweak the following:

* (LVM configuration) name of root disk "-root' instead of "-disk" (to match
our existing guests)
* make the guest configurations go to /etc/xen/guests instead of filling up
/etc/xen
* add an option for DRBD disk devices (details below)
* make the swap device a swapfile inside of the root disk

I've hacked around a little in the code, but I don't see a clean way to do
much of this stuff ...

Using DRBD for the disk device is easy and hard at the same time (of
course!) ... for the xen guest configuration, the disk line looks like:

  'drbd:guest-test-disk,xvda2,w'

where "drbd" is the disk type, "guest-test-disk" is the LV name (LVM), and
xvda2 is the disk partition to present to the client.

Now, to get fancier, you could add support to the /etc/drbd.conf and all of
that, but that can get pretty sticky and may not be what the end user
wants.  Checking for existing configuration entries, modifying/deleting
them, etc.  Also, the DRBD device could have an internal or external meta
device ... for internal, you need to grow the LV a little for it to hide in
... gets messy quick.

Anyway, I'm getting ahead of myself ... Let's start with the easy stuff and
what the proper method to recommend enhancements, changes, etc is.

Definately looks like a fun tool, tho!

Thanks!
Sam